Structure and method for manufacturing Group III-V composite Schottky contacts enhanced by a sulphur fluoride/phosphorus fluoride layer

1. A method for manufacturing a Schottky contact having high-temperature proof and oxidation resistance, comprising the following steps: (a) dipping a composite semiconductor substrate into a solution containing phosphorus pentasulphide/ammonia sulphide (P.sub.2 S.sub.5 /INH.sub.4).sub.2 S.sub.x) with a proportion of 0.05 g/ml for a dipping time of several minutes, and then drying said composite semiconductor substrate with nitrogen; (b) performing a fluoride treatment on said composite semiconductor substrate; (c) repeating steps (a)-(b) for several times; and (d) performing a UV ray treatment on said composite semiconductor substrate after step (c) for 3 mins. to form a thin sulphur fluoride/phosphorus fluoride layer.

2. The method for manufacturing a Schottky contact as claimed in claim 1, wherein said dipping time in step (a) is about 3 mins.

3. The method for manufacturing a Schottky contact as claimed in claim 1, wherein said fluoride in step (b) can be a hydrogen fluoride (HF) solution or carbon tetrafluoride (CF.sub.4).

4. The method for manufacturing, a Schottky contact as claimed in claim 1, wherein repeating 3 times in step (c) can obtain a preferable thin layer.

5. The method for manufacturing a Schottky contact as claimed in claim 1, further comprising the following step: (e) forming a Schotticy contact metal layer by evaporating or sputtering the surface of said thin layer with a precious metal.

6. The method for manufacturing a Schottky contact as claimed in claim 1, wherein said thin layer has a thickness of 50-150 .ANG..